Sustainable Liquid Desiccant System Research...Sustainable Liquid Desiccant System Research...
Transcript of Sustainable Liquid Desiccant System Research...Sustainable Liquid Desiccant System Research...
The material presented here is based upon work supported by the National Science Foundation under Award No. EEC-0813570, Grant Number EPSC-1101284 . Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.
Sustainable Liquid Desiccant System Research Mackenzie Betz , Esdras Murillo , Shan He , Ulrike Passe
Dallas Center-Grimes High School, Iowa State University
There are many techniques used for
cooling buildings, one method is to
dehumidify the air. Liquid desiccant
systems can be used to reduce the
relative humidity of a given area
30%- 80% if used correctly.
Desiccant systems use sorption
processes to remove water vapor
out of the air and then heat the
solution in a rechargeable box to
evaporate the excess water to be
expelled outside. Lowering the
relative humidity in a building
makes the air more comfortable,
and reduces the reliance of an air
conditioning system.
BACKGROUND ABSTRACT The goal of my research project was to find a desiccant
to be implemented into the liquid desiccant system and
reduce relative humidity by at least 30%. The current
desiccant being used is calcium chloride. The desiccant
system’s results were analyzed, the system was tested
many times to try to achieve 30% dehumidification.
Ideally once the system can reduce relative humidity 30%
it will be installed into the solar powered Interlock House
to reduce energy consumption by reducing the reliance of
the AC on electricity use. Organic desiccants were also
researched to improve the system’s results, as well as
remove some of the negative effects caused by CaCl .
RESEARCH QUESTIONS How much is the current liquid desiccant system lowering the relative humidity?
What organic desiccants can be implemented to improve the current liquid desiccant system?
METHODS The current desiccant, calcium chloride is averaging 10% dehumidification, in its most ideal
circumstances, and works best in high relative humidity input. Calcium chloride has not shown it can
decrease the absolute humidity by 30% consistently like needed, and is also causing corrosion on the
piping, that an organic desiccant would not. Many organic desiccants have a large percent
dehumidification at only 50% relative humidity input. Although organic desiccants tend to be more
expensive they wont cause corrosion and don’t require as strict of conditions as calcium chloride.
Suggested Desiccants
DISCUSSION & CONCLUSION
RESULTS & DATA ANALYSIS
OTHER WORK
ACKNOWLEDGEMENT I would like to thank CBiRC and Iowa State University for supporting the YES program, Adah Lesham, Stacy Renfrow, Diana Loutsch, and Yadira
Cano Camacho for their work. I would also like to thank Ulrike Passe, Shan He, Esdras Murillo for their mentorship and supervision during my
internship, Iowa NSF EPSCoR for funding, and Joshua Mangler for his recommendation.
REFERENCES
AH= Absolute Humidity
RH= Relative Humidity
Pws= Water Saturation Pressure
Pvw= Water Vapor Pressure
T=Temperature (Celsius)
A= 6.116441
m= 7.591386
Tn=240.7263
While keeping the input humidity constant,
this compares the absolute and relative
humidity. The AH shows a change, while the
RH is almost the same for input and output.
This shows that the output temperature of the
air is cooler than the input.
This data was taken as the input AH was
growing throughout the experiment. This
shows that the system achieves a higher
percent dehumidification when the input AH is
higher.
While the liquid desiccant system is running, sensors are
retrieving data which is used in the following equations to
find the absolute humidity and relative humidity. These
values are used with temperature to determine how the
air feels.
Teaching: Taught two classes of third and fourth graders
about thermo-radiation, heat transfer, and what
causes them to feel hot and cold.
Cauc, C.K., and W.M. Worek. “Cosorption Processes of Triethylene Glycol in a Packed-Bed Dehumidifier.” HVAC & R Research. Online:
Taylor & Francis, 2011. 189-210. Print.
Kazemi, Pezhman, and Roya Hamidi. "Sensitivity Analysis of a Natural Gas Triethylene Glycol Plant in Persian Gulf Region." Petroleum &
Coal. N.p., 9 Nov. 2010. Web. 17 July 2014.
<http://www.vurup.sk/sites/vurup.sk/archivedsite/www.vurup.sk/pc/vol53_2011/issue1/pdf/pc_1_2011_kazemi_101.pdf>.
Sun, Jin, and Robert W. Besant. International journal of heat and mass transfer. Oxford: Pergamon Press., 2005. Print.
Prices found at chemistrystore.com
Although silicon dioxide is cheaper, it
comes already in a water solution.
The triethylene glycol can have water
added to it and work efficiently, it also
has a stronger capability to remove
contaminants from the air.
Both desiccants are non-corrosive,
and preform best at room
temperature.
² Interlock House
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Liquid Desiccant System Diagram
Organic Desiccant Silicon Dioxide Triethylene Glycol
Regeneration Temperature
Up to 150˚C 60˚C - 240˚C
Sorption Process Adsorbs water Absorbs water
Removal Efficiency
Can drop RH to 40% Adsorbs 40% it's own weight
Has been proven to have 96% absorption efficiency
Price 1 Gallon = $16.48 1 Gallon = $27.80